Field of the Invention
The present invention relates to a semiconductor device, and more specifically to a technology for suppressing electric current consumption.
Description of Related Art
A semiconductor device in the related art, which is used for an imaging device, for example, such as a digital camera, includes a circuit that performs correlation double sampling processing on an output signal (a pixel signal) of a pixel, an amplification circuit that amplifies the pixel signal on which the correlation double sampling processing is performed, an A/D conversion circuit that performs A/D conversion of the amplified pixel signal, and the like. In this type of semiconductor device, because of the need to secure a dynamic range of a pixel signal, the pixel or the amplification circuit is caused to operate at a high power source voltage, and because of the need to realize a reduction in power consumption, the A/D conversion circuit is caused to operate at a low power source voltage. For this reason, this type of semiconductor device includes a level shift circuit for converting a signal level of the output signal of the pixel into a signal level suitable for the A/D conversion circuit in a low power source voltage system like Japanese Unexamined Patent Application, First Publication No 2000-224495.